TELCOM TCL1585

7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1584
TCL1585
TCL1585
TCL1587
TCL1587
7A / 5A / 4.6A / 3A, FAST RESPONSE, LOW DROPOUT
POSITIVE LINEAR VOLTAGE REGULATORS
FEATURES
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The TCL1584/1585/1587 are low dropout, positive linear voltage regulators. They have a maximum current
output specification of 7A, 5A, 4.6A and 3A respectively.
All three devices are supplied in fixed and adjustable output
voltage versions.
Good transient load response combined with low dropout voltage makes these devices ideal for the latest low
voltage microprocessor power supplies. Additionally, shortcircuit, thermal and safe operating area (SOA) protection is
provided internally to ensure reliable operation.
The TCL1587, TCL1585 and TCL1584 are available in
a 3-pin TO-220 tabbed power package and in a 3-pin surface
mount DDPAK-3 package.
Fixed and Adjustable Voltages ........ 1.5V and 3.3V
Optimized for Low Voltage Applications
Output Current Capability ..........7A / 5A / 4.6A / 3A
Guaranteed Dropout Voltage up to Full Rated
Output
Integrated Thermal and Short-Circuit Protection
Compact 3-Pin Surface-Mount and Thru-Hole
Standard Power Packages
VREF Accuracy ................................................. 2.0%
Load Regulation ............................................. 0.05%
APPLICATIONS
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PentiumTM*, PentiumProTM* CPU Power Supplies
PowerPCTM* CPU Power Supplies
PentiumProTM* System GTL+ Bus Terminators
Low-Voltage, High Speed Microprocessors
Post-Regulator for Switch-Mode Power Supplies
ORDERING INFORMATION
GENERAL DESCRIPTION
PIN CONFIGURATIONS
TO-220-3
1
2
DDPAK-3
1
3
2
3
VIN
VOUT
ADJ/GND
VIN
VOUT
TCL1584CEB
TCL1585CEB
TCL1587CEB
ADJ/GND
TCL1584CAB
TCL1585CAB
TCL1587CAB
NOTE: For TO-220 ΘJA = 53°C/W. For DDPAK-3 ΘJA = 76°C/W. ΘJA for both packages
are specified without external heat sinks. See Applications Section for details.
Part Number
Package
Temp. Range
TCL1584-3.3CAB
TCL1584-3.3CEB
TCL1584-ADJCAB
TCL1584-ADJCEB
TO-220-3
DDPAK-3
TO-220-3
DDPAK-3
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
TCL1585-1.5CAB
TCL1585-1.5CEB
TCL1585-3.3CAB
TCL1585-3.3CEB
TCL1585-ADJCAB
TCL1585-ADJCEB
TO-220-3
DDPAK-3
TO-220-3
DDPAK-3
TO-220-3
DDPAK-3
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
TCL1587-1.5CAB
TCL1587-1.5CEB
TCL1587-3.3CAB
TCL1587-3.3CEB
TCL1587-ADJCAB
TCL1587-ADJCEB
TO-220-3
DDPAK-3
TO-220-3
DDPAK-3
TO-220-3
DDPAK-3
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
0°C to + 70°C
TYPICAL OPERATING CIRCUIT
Adjustable Output Voltage Version
Fixed Output Voltage Version
VIN
VIN = 5V
C1 = 10µF
VOUT
TCL158x-3.3
GND
VOUT = 3.3V
VIN = 5V
C1 = 10µF
C2*
(Tantalum)
VOUT =
(1+ R1/R2)VREF
VOUT
VIN
TCL158x
ADJ
R1
R2
*NOTE:
C2 is required to ensure output stability. Minimum 22µF (TCL1584) or 10µF (TCL1585/7),
low ESR tantalum type. Larger values may be required for high output current transient
regulation. See Applications section.
*All Trademarks and Trade Names are the property of their respective owners.
TCL1584/1585/1587-04 6/6/97
TCL1584/1585/1587-04 6/6/97
1
TelCom Semiconductor reserves the right to make changes in the circuitry and specifications of its devices.
C2*
(Tantalum)
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
ABSOLUTE MAXIMUM RATINGS*
*This is a stress rating only, and functional operation of the device at these
or any other conditions beyond those indicated in the operation section of
the specifications is not implied. Exposure to absolute maximum ratings
conditions for extended periods of time may affect device reliability.
Input Voltage (VIN to GND) ...........................................7V
Operating Junction Temperature Range
Control Circuitry ................................... 0°C to +125°C
Output Transistor ................................. 0°C to +150°C
Power Dissipation ..................... See Applications Section
Storage Temperature (unbiased) .......... – 65°C to +150°C
Lead Temperature (Soldering, 10 sec) ................. +300°C
ELECTRICAL CHARACTERISTICS: TA = Operating Temperature Range, 4.75V ≤ VIN ≤ 5.25V, unless
otherwise specified.
Parameter Device
Test Conditions
1.5V ≤ (VIN – VOUT) ≤ 3V, 10mA ≤ IOUT ≤ 7A
1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 4.6A, TJ ≥ 25°C
1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 4A, TJ < 25°C
TCL1587
1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ 3A
Output
TCL1587-1.5
4.75V ≤ VIN ≤ 7V, 0mA ≤ IOUT ≤ 3A
Voltage
TCL1584-3.3
4.75V ≤ VIN ≤ 6.3V, 0mA ≤ IOUT ≤ 7A
TCL1585-3.3
4.75V ≤ VIN ≤ 7V, 0mA ≤ IOUT ≤ 4.6A, TJ ≥ 25°C
4.75V ≤ VIN ≤ 7V, 0mA ≤ IOUT ≤ 4A, TJ < 25°C
TCL1587-3.3
4.75V ≤ VIN ≤ 7V, 0mA ≤ IOUT ≤ 3A
Line
TCL1584/5/7
2.75V ≤ VIN ≤ 7V, IOUT = 10mA
Regulation TCL1587-1.5
4.75V ≤ VIN ≤ 7V, IOUT = 0mA
(Notes 1, 2) TCL1584/5/7-3.3 4.75V ≤ VIN ≤ 7V, IOUT = 0mA
Load
TCL1584/5/7
(VIN – VOUT) = 3V, TJ = 25°C, 10mA ≤ IOUT ≤ IFULL LOAD
Regulation TCL1587-1.5
VIN = 5V, TJ = 25°C, 0mA ≤ IOUT ≤ IFULL LOAD
(Notes 1, TCL1584/5/7-3.3 VIN = 5V, TJ = 25°C, 0mA ≤ IOUT ≤ IFULL LOAD
2, 3)
Over Operating Temperature Range
Dropout
TCL1585/7
∆VREF = 1%, IOUT = 3A
Voltage
TCL1587-1.5
∆VOUT = 1%, IOUT = 3A
TCL1585/7-3.3
∆VOUT = 1%, IOUT = 3A
TCL1585
∆VREF = 1%, IOUT = 4.6A, TJ ≥ 25°C
∆VREF = 1%, IOUT = 4A, TJ < 25°C
TCL1585-3.3
∆VOUT = 1%, IOUT = 4.6A, TJ ≥ 25°C
∆VOUT = 1%, IOUT = 4A, TJ < 25°C
TCL1584
∆VREF = 1%, IOUT = 6A
TCL1584-3.3
∆VOUT = 1%, IOUT = 6A: TJ ≥ 25°C
TJ < 25°C
TCL1584
∆VREF = 1%, IOUT = 7A
TCL1584-3.3
∆VOUT = 1%, IOUT = 7A
Current
TCL1584
(VIN – VOUT) = 3V
7.10
Limit
TCL1584-3.3
(VIN – VOUT) = 3V
(Note 3)
TCL1585
(VIN – VOUT) = 5.5V: TJ < 25°C
TCL1585-3.3
(VIN – VOUT) = 5.5V: TJ ≥ 25°C
TCL1587
(VIN – VOUT) = 5.5V
TCL1587-1.5
(VIN – VOUT) = 5.5V
TCL1587-3.3
(VIN – VOUT) = 5.5V
Temperature TBD
TBD
Coefficient
ADJ Pin
TCL1584/5/7
Current
Reference TCL1584
Voltage
TCL1585
TCL1584/1585/1587-04 6/6/97
2
Min
Typ
Max
Unit
1.225
1.25
1.275
V
3.235
3.30
3.365
V
—
0.005
0.2
%
—
0.05
0.3
%
—
—
0.05
1.15
0.5
1.30
V
—
1.20
1.40
V
—
—
—
1.20
1.30
1.25
1.30
1.35
1.40
V
V
8.25
—
A
|
4.10
4.60
3.10
5.25
5.25
3.75
—
A
—
A
—
55
120
µA
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
ELECTRICAL CHARACTERISTICS: (Cont.) TA = Operating Temperature Range, 4.75V ≤ VIN ≤ 5.25V,
unless otherwise specified.
Parameter Device
Test Conditions
Min
Typ
Max
Unit
ADJ Pin
Current
Change
(Note 3)
Minimum
Load
Current
Quiescent
Current
Ripple
Rejection
TCL1584
TCL1585/7
1.5V ≤ (VIN – VOUT) ≤ 3V, 10mA ≤ IOUT ≤ IFULL LOAD
1.5V ≤ (VIN – VOUT) ≤ 5.75V, 10mA ≤ IOUT ≤ IFULL LOAD
—
0.2
5
µA
TCL1584/5/7
1.5V ≤ (VIN –VOUT) ≤ 5.75V
—
2
10
mA
—
8
13
mA
60
72
—
dB
—
0.004
0.02
%/W
—
0.5
—
%
—
0.03
1.0
%
—
0.003
—
%
—
—
—
—
—
—
—
—
—
—
0.65/2.7
0.7/3.0
0.7/3.0
0.7/3.0
0.7/3.0
°C/W
°C/W
°C/W
°C/W
°C/W
VIN = 5V
VIN = 5V
f = 120Hz, COUT = 25µF Tant. (VIN – VOUT) = 2.5V, IOUT = 7A
f = 120Hz, COUT = 25µF Tant., VIN = 5.8V, IOUT = 7A
f = 120Hz, COUT = 25µF Tant., (VIN – VOUT) = 3V, IOUT = 4.6A, TJ ≥ 25°C
f = 120Hz, COUT = 25µF Tant., (VIN – VOUT) = 3V, IOUT = 4A, TJ ≤ 25°C
TCL1585-3.3
f = 120Hz, COUT = 25µF Tant.,VIN = 6.3V, IOUT = 4.6A, TJ ≥ 25°C
f = 120Hz, COUT = 25µF Tant.,VIN = 6.3V, IOUT = 4.6A, TJ ≤ 25°C
TCL1587
f = 120Hz, COUT = 25µF Tant., (VIN – VOUT) = 3V, IOUT = 3A
TCL1587-1.5
f = 120Hz, COUT = 25µF Tant., VIN = 5.0V, IOUT = 3A
TCL1587-3.3
f = 120Hz, COUT = 25µF Tant., VIN = 6.3V, IOUT = 3A
Thermal
TCL1584/5/7
TA = 25°C, 30msec Pulse
Regulation TCL1587-1.5
TA = 25°C, 30msec Pulse
TCL1584/5/7-3.3 TA = 25°C, 30msec Pulse
Temperature
VIN = 5V, IOUT = 0.5A
Stability
Long Term
TA = 125°C, 1000Hrs.
Stability
RMS
TA = 25°C, 10Hz ≤ f ≤ 10kHz
Output
Noise (%
of VOUT)
Thermal
TCL1584
“A” pkg. (TO-220): Control Circuitry/Power Transistor
Resistance TCL1585
“A” pkg. (TO-220): Control Circuitry/Power Transistor
(Junction to TCL1585
“E” pkg. (TO-263): Control Circuitry/Power Transistor
Case, ΘJA) TCL1587
“A” pkg. (TO-220): Control Circuitry/Power Transistor
TCL1587
“E” pkg. (TO-263): Control Circuitry/Power Transistor
TCL1587-1.5
TCL1584/5/7-3.3
TCL1584
TCL1584-3.3
TCL1585
NOTES: 1. See thermal regulation specifications for changes in output voltage due to heating effects. Load and line regulation are measured at a constant
junction temperature by low duty cycle pulse testing.
2. Load and line regulation are guaranteed up to the maximum power dissipation (25W for the TCL1584 in “A” pkg., 26.5W for the TCL1585 in
“A” pkg., 18W for the TCL1587 in “A” pkg.). Power dissipation is determined by input/output voltage differential and output current. Guaranteed
maximum output current/power will not be available over full input/output voltage range.
3. IFULL LOAD is defined as the maximum value of output load current as a function of input-to-output voltage. IFULL LOAD is a nominal 7A for
TCL1584, decreasing to approximately 3A as VIN – VOUT increases from 3V to 7V. For all other fixed voltage TCL1585’s, IFULL LOAD is 4A. For
the TCL1587, IFULL LOAD is 3A. The TCL1585 and 1587 have constant current limit with respect to VIN and VOUT.
TCL1584/1585/1587-04 6/6/97
3
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
Typical Dropout Voltage vs. Output Current
INPUT/OUTPUT DIFFERENTIAL (V)
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0
IFULL LOAD
OUTPUT CURRENT (A)
SIMPLIFIED SCHEMATIC
VIN
+
–
TCL1584/5/7
VOUT
THERMAL
LIMIT
ADJ
GND
FOR FIXED VOLTAGE DEVICE
TCL1584/1585/1587-04 6/6/97
4
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
APPLICATIONS
General
age response to step load current change is illustrated in
Figure 1. The capacitor’s ESR and ESL cause immediate
step changes in the output voltage. These are calculated as
follows:
The TCL158x family of devices combine high current
output (up to 7A) with low dropout voltage and built-in fault
protection in a traditional three-terminal LDO format. All
three device types are available in fixed output voltage and
adjustable output versions. Fault protection includes shortcircuit current limit, over-temperature limit, and safe-operating-area (SOA) governing.
These devices are pin-compatible upgrades for the
1083/1084/1085 family of LDO’s. However, the TCL158x
family delivers lower dropout voltage, faster load transient
response and improved internal frequency compensation.
Maximum supply voltage rating is 7.0V.
Modern processors cycle load current from near zero to
several amps in a time period measured in tens of nanoseconds. Load step response requirements are worsened by
tighter output voltage tolerances. The TCL1584/85/87 family of regulators meets these stringent requirements without
an obnoxious amount of output capacitance, saving both
board space and cost.
∆VESR = ∆I x ESR
DVESL = DI/Dt x ESL
To reduce the initial voltage droop, one should select
low ESR and ESL capacitors. It should also be noted that the
ESR effect is multiplied by absolute change in load current
while the ESL effect is multiplied by the rate of change in load
current. After the initial voltage drop, the capacitor value
dominates the rate of change in voltage. This rate is calculated as follows:
∆V = ∆t x ∆I/C
ESR
EFFECTS
Stability and Transient Response
ESL
EFFECTS
Like most low dropout voltage regulators, the TCL158x
devices require the use of output capacitors to maintain
stability. Normally a 22µF solid tantalum or a 100µF aluminum electrolytic unit will ensure stability over all operating
conditions. Keep in mind that commercially available capacitors can have significant non-ideal effects such as
capacitance value tolerance, temperature coefficient, ESR,
ESL. The TCL158x devices are optimized for use with low
ESR (<1Ω) capacitors.
On the adjustable voltage versions, bypassing the ADJ
pin will improve ripple rejection and transient response. This
is discussed in the Ripple Rejection section. This bypassing
increases the required output capacitance value. The previously suggested minimum values (22µF and 100µF) take
this into account. If no bypassing is used, lower values of
output capacitance may be used.
Transient regulation is directly related to output capacitance value. For applications which require large load current step changes, it is recommended that large output
capacitors (>100µF) be used. The value of the output
capacitor can be increased without limit and will only improve transient regulation.
In a typical high-performance microprocessor application, the sudden transients can be so fast that the output
decoupling network must handle the sudden current demand until the internal voltage regulator is able to respond.
In this case the non-ideal effects of the output capacitor are
critical in determining the regulator’s response. Output voltTCL1584/1585/1587-04 6/6/97
SLOPE,
CAPACITANCE
EFFECTS
V = ∆I
t
C
POINT AT WHICH REGULATOR
TAKES CONTROL
Figure 1. Transient Load Voltage Response
Typically high quality ceramic and tantalum capacitors
must be used in combination to minimize ESR and maximize
C. This decoupling network must also be placed close to the
microprocessor to reduce ESL (parasitic board trace inductance). If possible, the capacitors should be placed inside
the microprocessor socket cavity. Of course, robust power
and ground planes will also improve performance by reducing parasitic voltage drops.
The TCL1584 has an adaptive current limiting scheme
where to ensure SOA for the output transistor, the current
limit is reduced for increasing input to output differential. This
means that the TCL1584 exhibits a negative resistance
characteristic under certain conditions. This is a common
technique in LDO design to ensure SOA - especially LDO’s
with high maximum input voltage ratings. This negative
resistance can interact with the external capacitance and
inductance and cause oscillations during current limit. This
effect is highly dependent on system parameters and is
difficult to predict. However this oscillation, if it occurs, will
not damage the regulator and can be ignored if the system
5
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
Overload Recovery
parameters will allow it. Typically, increasing the output
capacitance helps reduce the oscillation. NOTE: The
TCL1585 and TCL1584 have fixed current limit over the
entire voltage range and are not susceptible to this phenomenon.
The built-in Short Circuit and Safe-Operating-Area (SOA)
protection function of the TCL158x family can cause secondary effects which must be considered for robust system
design. The behavior of the regulator under heavy loads
(short circuit) at start-up is such that the output voltage will
remain low while sourcing maximum current until the load is
removed or reduced. Normally, the output voltage will rise as
the load is reduced and trace a line I-V relationship according to the SOA limit. If the load line intersects this output
curve at two points the output voltage may not recover from
the heavy load/short-circuit condition. This condition is illustrated in Figure 3. The current limit constraint does not allow
any load point above it and the load line is defined absolutely
by the I-V characteristics of the load (a resistor, in this case).
Under these conditions it may be necessary to cycle the
power supply off and then on again. This phenomenon is
common for LDO’s with fold-back current limiting schemes.
NOTE: Overload recovery is always guaranteed on the
TCL1585 and TCL1587 because of the constant current
limit characteristic.
Protection Diodes
The TCL158x family of devices do not normally require
any external current limiting circuitry such as protection
diodes, frequently used with older LDO regulators. A diode
is internally present between the output and input which is
capable of handling short-duration surge currents of up to
100A. This capability typically ensures safe operation except for the case where output capacitance is exceedingly
large (>1000µF) and the input is suddenly shorted to ground.
This situation can produce excessive reverse current in the
device - enough to cause damage. An external high current
diode should be used as shown in Figure 2.
The ADJ pin does not normally need protection diodes
either. It can handle ±7V without any performance degradation or device damage. Current at this pin is internally limited
by a series resistor so the bypass capacitors do not present
any danger. Of course, exceeding 7V differential between
any two pins will cause catastrophic junction breakdowns
and possible damage to the device.
Ripple Rejection
A typical ripple rejection curve for the fixed output
voltage devices is shown in Figure 3. It is possible to obtain
improved performance in ripple rejection by using the adjustable output TCL158x with a bypass capacitor (CADJ)
shown in Figure 2. This capacitor should be chosen to have
a value such that its impedance at the ripple frequency is
less than R1 (see Figure 2.). Usually this is on the order of
100Ω. Example: If R1 = 100Ω and fRIPPLE = 120Hz, the
bypass capacitor should be chosen to be 22µF or greater. If
these conditions are met the ripple rejection will be improved
by a factor of VOUT/1.25 when compared to the performance
of the fixed output devices.
D1
1N4002
(OPTIONAL)
VIN
IN TCL1584-3.3 OUT
GND
+
VOUT
+
C1
10µF
C2
22µF
D1
1N4002
(OPTIONAL)
VIN
IN
C1 +
10µF
TCL1584
ADJ
+
Current Limit Curve
VOUT
OUT
CADJ
R1
+
Unrecoverable
I-V Point
IOUT
C2
22µF
Load Line
R2
VIN – VOUT (Constant VIN)
Figure 2. Protection Diodes and CADJ
Figure 3. Overload Recovery
TCL1584/1585/1587-04 6/6/97
6
Start Up
Point
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
Output Voltage
RP
PARASITIC
LINE RESISTANCE
The output voltage for the fixed output versions of the
TCL158x is set internally and cannot be adjusted. For the
adjustable output versions, the output voltage is set by two
external resistors: R1 and R2 (see Figure 3). A 1.25V
reference voltage is maintained between the OUTPUT pin
and the ADJ pin. NOTE: the ADJ pin typically will source
55µA. R1 should be chosen to conduct at least the specified
minimum load current of 10mA (i.e. at most 125Ω). Now R2
will determine the total output voltage according to the
equation below:
VIN
IN TCL1584-3.3 OUT
GND
RL
Figure 5. Connection for Best Load Regulation
VOUT = VREF(1+ R2/R1) + R2(IADJ)
In both cases, because the effect of parasitic trace
resistance (RP) cannot be completely eliminated, it is important to keep the positive output lead as short as possible.
Otherwise, at high output currents, the load regulation will
degrade appreciably. Example:
The contribution due to the IADJ term is relatively small
as IADJ is only 55µA compared to 10mA for the total current
in the adjust circuit.
VIN
IN
C1 +
10µF
TCL1584
ADJ
RP = 5mΩ
IOUT = 3A
VDROP = (0.005) x (3) = 15mV
VOUT
OUT
VREF
R1
C2
22µF
IADJ
55µA
(
VOUT = VREF 1+ R2
R1
) + IADJ (R2)
RP
PARASITIC
LINE RESISTANCE
R2
VIN
IN
TCL1584
OUT
ADJ
Figure 4. Adjustable Voltage Regulator
R1*
Load Regulation
RL
Because the TCL158x family are three terminal devices, it is not possible to perform true Kelvin load voltage
sensing. Therefore load regulation is limited somewhat by
parasitic trace resistance. The load regulation specifications
are measured directly at the TCL158x package. To minimize
degradation in load regulation performance the following
guidelines should be used.
For fixed voltage devices, the GND pin should be
connected directly to the negative side of the load instead of
to a common ground bus. This provides Kelvin sensing at
the negative side while the positive side is still limited by RP
(See Figure 5).
For adjustable output devices, the bottom of R2 connects to the negative side of the load. For the positive side,
best regulation is obtained when the top of R1 is connected
directly to the TCL158x and not to the load (See Figure 6).
If R1 connects to the load the effective resistance between
the output and the load is:
R2*
*CONNECT R1 TO CASE
CONNECT R2 TO LOAD
Figure 6. Connection for Best Load Regulation
Thermal Considerations
The TCL158x family includes built-in thermal overload
protection. However, maximum operating junction temperature must not be exceeded for any condition. Since these
devices are capable of dissipating up to 25W or more under
some conditions, careful thermal design is required for
reliable, continuous operation. In most cases, external heat
sinking will be required.
RP x (1 + R2/R1)
TCL1584/1585/1587-04 6/6/97
7
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
When generating the overall thermal design, it is important to consider all sources of thermal resistance between
the silicon die and ambient - junction-to-case (ΘJC), case-toheat sink (ΘCH), heat sink-to-ambient (ΘHA). NOTE: there
are two separate ΘJC specifications for the power transistor
and the control circuitry. Both junction temperatures must be
calculated and kept under each respective maximum limit to
ensure proper operation. This ΘJC is for the physical path
between the die and the bottom metal portion of the case
(both TO-220 and DDPAK-3. Heat flow will be greatest
through this path. It is important that good thermal coupling
is made between the case and heat sink. If electrical
isolation from the heat sink is not required, it is recommended that thermally conductive compound be used.
Otherwise, use a thermally conductive dielectric spacer.
The following is a thermal design example:
NOTE: Without heat sinking, the thermal resistance for the
TO-220 and DDPAK-3 packages are 53°C/W and
76°C/W respectively.
Using a TCL1585-3.3 in a TO-220 package:
Assumptions:
TA = +70°C
VIN = 5.25V (5V + 5%)
VOUT = 3.30V
IOUT = 4.6A
ΘHA = 3.5°C/W (heat sink-to-ambient)
ΘCH = 1.5°C/W (case-to-heat sink)
ΘJC = 3°C/W (power transistor)
ΘJC = 0.7°C/W (control circuitry)
Power dissipation:
PD = (VIN – VOUT)(IOUT) = (5.25 – 3.3)(4.6) = 8.97W
Junction Temperatures:
TJ = TA + PD(ΘHA + ΘCH + ΘJC)
Control Circuitry:
TJ = 70 + 8.97(3.5 + 1.5 + 0.7) = 121.1°C
Power Transistor:
TJ = 70 + 8.97(3.5 + 1.5 + 3) = 141.8°C
These values for TJ fall within the maximum allowed
junction temperature for each die section indicating adequate heat sinking with some margin.
TCL1584/1585/1587-04 6/6/97
8
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
TYPICAL APPLICATIONS
Typical Intel™* 486Dx4 Microprocessor Application
PLACE AT MICROPROCESSOR SOCKET VCC PINS
VIN ≥ 4.75V
VIN
3.30V
3A
VOUT
TCL1587-3.3
C1
10µF
10V
C2
22µF
10V
GND
C3 TO C6
47µF
10V
C7 TO C15
0.1µF
C16 TO C24
0.01µF
ESR OF THE 47µF IS < 0.1Ω
Intel™* 90MHz Pentium™* Power Supply
THERMALLOY
7020B-MT
4.75V TO 5.25V
C1 TO C3
220µF
10V
AVX TPS
3 EACH
VIN
TCL1585
ADJ
PLACE IN MICROPROCESSOR
SOCKET CAVITY
3.38V
4.6A
VOUT
R1
110Ω
0.1%
C5 TO C10
100µF
10V
AVX TPS
6 EACH
R2
187Ω
0.1%
C4
330µF
16V
AVX X7R 0805
C11 TO C20
1µF
16V
AVX Y5V 0805
10 EACH
AVX Corp. (803) 448-9411
Sanyo Video Components (USA) Corp. (619) 661-6322
Thermalloy Inc. (214) 243-4321
DO NOT SUBSTITUTE COMPONENTS
Transient Response for 3.8A Load Current Step*
VOUT
50mV/DIV
IOUT
2A/DIV
100µsec/DIV
*TRANSIENT RESPONSE MEASURED WITH AN
INTEL POWER VALIDATOR™. VOUT IS MEASURED
AT THE POWER VALIDATOR.
All Trademarks and Trade Names are the property of their respective owners.
TCL1584/1585/1587-04 6/6/97
9
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
TYPICAL APPLICATIONS (Cont.)
Typical Intel™* Pentium™* Pro GTL+ Bus Terminator Application Using TCL1587-1.5
VOUT = 1.5V @ 3A
VIN = 5V or 3.3V
VIN
C1 = 10µF
VOUT
TCL1587-1.5
GND
C2 = 10µF
(Tantalum)
RTERM
C3 =1µF x 5 = 100Ω x 71
(Ceramic)
Lines
RREF
GTL+ Bus (ZO)
RTERM
= 100Ω x 71
Lines
VOUT = 1.5V @ 3A
VIN = 5V or 3.3V
C1 = 10µF
VIN
VREF = 1.0V
2RREF
VOUT
TCL1587-1.5
GND
C2 = 10µF
(Tantalum)
C3 = 1µF x 5
(Ceramic)
NOTES: 1. It is recommended that the GTL+ bus be terminated at each end by a separate regulator to avoid power distribution losses.
2. The GTL+ bus transmission line symbol will consist of all the components (chip set IC's) on the GTL+ bus.
3. RREF and 2RREF should be chosen such that VREF loading does not appreciably degrade VREF regulation.
Values <100 ohms should suffice for most applications.
4. RTERM will be determined by individual bus physical/electrical parameters. See CPU manufacturer documentation for
application information.
*All Trademarks and Trade Names are the property of their respective owners.
TCL1584/1585/1587-04 6/6/97
10
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
TYPICAL CHARACTERISTICS
SHORT-CIRCUIT CURRENT (A)
1.3
T = – 5°C
1.2
1.1
1.0
T = 125°C
0.9
T = 25°C
0.8
0.7
0.6
0.5
INDICATES GUARANTEED TEST POINT
0
1
2
3
4
5
8
6
T = 125°C
T = 25°C
4
MINIMUM
2
0
6
0
7
OUTPUT CURRENT (A)
1
2
3
4
5
6
7
INPUT/OUTPUT DIFFERENTIAL (V)
TCL1585 Dropout Voltage vs.
Output Current
T = – 5°C
1.2
1.1
1.0
T = 125°C
0.9
T = 25°C
0.8
0.7
0.6
INDICATES GUARANTEED TEST POINT
0.5
0
1
2
3
4
5.5
5.0
4.5
4.0
–75 –50 –25 0 25 50 75 100 125150 175
5
OUTPUT CURRENT (A)
SHORT-CIRCUIT CURRENT (A)
5.0
1.3
T = – 5°C
1.1
T = 25°C
0.9
T = 125°C
0.8
0.7
0.6
INDICATES GUARANTEED TEST POINT
0.5
0
0.5
1.0
1.5
2.0
OUTPUT CURRENT (A)
TCL1584/1585/1587-04 6/6/97
2.5
–0.10
–0.15
–0.20
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
3.0
4.5
4.0
3.5
3.0
–75 –50 –25 0 25 50 75 100 125150 175
TEMPERATURE (°C)
11
∆I = 4.6A
0.05
0
–0.05
–0.10
–0.15
–0.20
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
TCL1587 Short-Circuit Current
vs. Temperature
1.5
1.4
1.0
–0.05
TEMPERATURE (°C)
TCL1587 Dropout Voltage vs.
Output Current
1.2
0
0.10
OUTPUT VOLTAGE DEVIATION (%)
SHORT-CIRCUIT CURRENT (A)
1.4
∆I = 7A
0.05
TCL1585 Load Regulation
vs. Temperature
6.0
1.3
0.10
TCL1585 Short-Circuit Current
vs. Temperature
1.5
DROPOUT VOLTAGE (V)
T = – 5°C
TCL1587 Load Regulation
vs. Temperature
OUTPUT VOLTAGE DEVIATION (%)
DROPOUT VOLTAGE (V)
1.4
OUTPUT VOLTAGE DEVIATION (%)
10
1.5
DROPOUT VOLTAGE (V)
TCL1584 Load Regulation
vs. Temperature
TCL1584 Short Circuit Current
vs. Input/Output Differential
TCL1584 Dropout Voltage vs.
Output Current
0.10
∆I = 3A
0.05
0
–0.05
–0.10
–0.15
–0.20
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
TYPICAL CHARACTERISTICS (Cont.)
3.70
1.270
3.65
1.265
3.60
1.255
1.250
1.245
1.240
1.235
3.55
3.50
VOUT = 3.45V
3.45
VOUT = 3.38V
3.40
3.35
VOUT = 3.3V
3.30
3.60
3.55
3.50
3.45
3.40
3.35
VOUT = 3.3V
3.30
3.25
3.25
1.255
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
3.20
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
3.20
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
TCL1584/5/7 Adjust Pin Current
vs. Temperature
4
3
2
1
0
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
100
13
90
12
80
70
60
50
40
30
20
10
50
40
TCL1584: (VIN – VOUT) ≤ 2.5V
TCL1584/87 (VIN – VOUT) ≤ 3V
0.5V ≤ VRIPPLE ≤ 2V
IOUT = IFULL LOAD
30
20
10
10
100
1k
10k
TCL1584
25
FREQUENCY (Hz)
20
TCL1587
15
10
15
10
0
50 60 70 80 90 100 110 120 130 140 150
CASE TEMPERATURE (°C)
*AS LIMITED BY MAXIMUM JUNCTION
TEMPERATURE
TCL1584/1585/1587-04 6/6/97
20
5
0
100k
4
30
TCL1585
5
0
6
5
TCL1584 Maximum Power
Dissipation*
POWER (W)
POWER (W)
60
8
7
TCL1585/7 Maximum Power
Dissipation*
25
70
9
3
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
30
80
11
10
0
–75 –50 –25 0 25 50 75 100 125 150 175
TEMPERATURE (°C)
TCL1584/5/7 Ripple Rejection
vs. Frequency
90
TCL1584/5/7-3.xx Quiescent
Current vs. Temperature
QUIESCENT CURRENT (mA)
ADJUST PIN CURRENT (µA)
5
MINIMUM LOAD CURRENT (mA)
3.65
1.230
TCL1584/5/7 Minimum Load Current
vs. Temperature
RIPPLE REJECTION (dB)
3.70
VOUT SET WITH 1% RESISTORS
VOUT = 3.6V
OUTPUT VOLTAGE (V)
1.275
1.260
TCL1584/5/7-3.3 Output Voltage
vs.Temperature
Output Voltage vs Temperature
Using Adjustable TCL1584/5/7
OUTPUT VOLTAGE (V)
REFERENCE VOLTAGE (V)
TCL1584/5/7 Reference Voltage
vs. Temperature
12
50 60 70 80 90 100 110 120 130 140 150
CASE TEMPERATURE (°C)
*AS LIMITED BY MAXIMUM JUNCTION
TEMPERATURE
7A / 5A / 4.6A / 3A, FAST RESPONSE,
LOW DROPOUT POSITIVE LINEAR
VOLTAGE REGULATORS
PRELIMINARY INFORMATION
TCL1584
TCL1585
TCL1587
PACKAGE DIMENSIONS
DDPAK-3
.183 (4.65)
.170 (4.32)
.410 (10.41)
.385 (9.78)
.067 (1.70)
.045 (1.14)
.055 (1.40)
.045 (1.14)
3° - 7°
(5x)
.370 (9.40)
.329 (8.38)
.010 (0.25)
.000 (0.00)
.605 (15.37)
.549 (13.95)
0.26 (0.66)
0.14 (0.36)
.051 (1.30)
.049 (1.24)
.110 (2.79)
.068 (1.72)
.037 (0.94)
.026 (0.66)
0° - 8°
.100 (2.54) TYP.
TO-220-3
.113 (2.87)
.103 (2.62)
.410 (10.41)
.390 (9.91)
.156 (3.96)
.146 (3.71)
DIA.
.185 (4.70)
.165 (4.19)
.055 (1.40)
.045 (1.14)
.258 (6.55)
.230 (5.84)
.594 (15.09)
.569 (14.45)
3° - 7.5°
5 PLCS.
.244 (6.20)
.234 (5.94)
.560 (14.22)
.518 (13.16)
.055 (1.40)
.045 (1.14)
.0.20 (0.51)
.012 (0.30)
.037 (0.94)
.027 (0.69)
.105 (2.67)
.095 (2.41)
.115 (2.92)
.095 (2.41)
.205 (5.21)
.195 (4.95)
Dimensions: inches (mm)
Sales Offices
TelCom Semiconductor
1300 Terra Bella Avenue
P.O. Box 7267
Mountain View, CA 94039-7267
TEL: 415-968-9241
FAX: 415-967-1590
E-Mail: [email protected]
TCL1584/1585/1587-04 6/6/97
TelCom Semiconductor
Austin Product Center
9101 Burnet Rd. Suite 214
Austin, TX 78758
TEL: 512-873-7100
FAX: 512-873-8236
13
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Hong Kong
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